Growth Kinetics and Viability Studies of Common Probiotic Bacteria on Date Syrup

Date syrup is a proved inexpensive functional food with increasing demand in the consumer market. It contains many functional components such as polyphenols, carotenoids, and phytosterols along with high amount of total sugars. Date syrup, therefore, could be a good culture for probiotic bacteria to develop a functional fermented beverage. The objective of the present work is to study the growth and survival of two probiotic bacteria, Lactobacillus sp. and Bifidobacetrium sp. in unbleached date syrup. The growth kinetics, pH, total sugars, total organic acids, and total phenolic content were investigated over a 5-day fermentation cycle at 37°C, and cell viability was determined for 8 weeks at 2-4°C. Both species were found growing in date syrup without any additional nutrient requirements and increased to more than 10⁶cfu/mL after 24 h. Lactobacillus sp. shown a more net decrease in pH with high sugar consumption and much better growth rate than Bifidobacterium sp. An insignificant difference in values of total phenolics was observed. This study proves that date syrup can be used in the development of a probiotic beverage and the common probiotic bacteria shows a promising growth on this plant product which is abundent in Middle East and North Africa (MENA) region.